论文标题
固体非线性光学响应中的微观电子动力学
Microscopic electron dynamics in nonlinear optical response of solids
论文作者
论文摘要
我们研究了Floquet理论中晶体固体非线性光学响应的显微镜特性，并证明光学诱导的显微镜电荷分布表现出复杂的空间结构和非平凡性能。它们的空间对称性和时间行为受晶体对称性的控制。我们发现，即使禁止晶体的宏观光学响应，微观光学响应实际上也可能是非零的。在这种情况下，即使每个单位细胞的时间依赖性偶极矩的相应傅立叶成分消失，光学诱导的电荷重新分布也可能是相当大的。我们开发了一种方法，可以通过亚周期分辨X射线光波混合完全重建微观光学诱导的电荷分布。我们还展示了如何在此框架内瞬时微观诱导的电子电流流动的方向。
We investigate the microscopic properties of the nonlinear optical response of crystalline solids within Floquet theory, and demonstrate that optically-induced microscopic charge distributions display complex spatial structure and nontrivial properties. Their spatial symmetry and temporal behavior are governed by crystal symmetries. We find that even when a macroscopic optical response of a crystal is forbidden, the microscopic optical response can, in fact, be nonzero. In such a case, the optically-induced charge redistribution can be considerable, even though the corresponding Fourier component of the time-dependent dipole moment per unit cell vanishes. We develop a method that makes it possible to completely reconstruct the microscopic optically-induced charge distributions by means of subcycle-resolved x-ray-optical wave mixing. We also show how, within this framework, the direction of the instantaneous microscopic optically-induced electron current flow can be revealed.
